Revision bb143f814ea488769ca2e79e0b376139cb5f134b authored by Vineet Gupta on 23 February 2016, 06:25:16 UTC, committed by Vineet Gupta on 24 February 2016, 05:37:28 UTC
ARConnect/MCIP Inter-Core-Interrupt module can't send interrupt to local core. So use core intc capability to trigger software interrupt to self, using an unsued IRQ #21. This showed up as csd deadlock with LTP trace_sched on a dual core system. This test acts as scheduler fuzzer, triggering all sorts of schedulting activity. Trouble starts with IPI to self, which doesn't get delivered (effectively lost due to H/w capability), but the msg intended to be sent remain enqueued in per-cpu @ipi_data. All subsequent IPIs to this core from other cores get elided due to the IPI coalescing optimization in ipi_send_msg_one() where a pending msg implies an IPI already sent and assumes other core is yet to ack it. After the elided IPI, other core simply goes into csd_lock_wait() but never comes out as this core never sees the interrupt. Fixes STAR 9001008624 Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> [4.2] Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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File | Mode | Size |
---|---|---|
Kconfig | -rw-r--r-- | 2.7 KB |
Makefile | -rw-r--r-- | 159 bytes |
af_ipx.c | -rw-r--r-- | 49.6 KB |
ipx_proc.c | -rw-r--r-- | 7.9 KB |
ipx_route.c | -rw-r--r-- | 6.6 KB |
pe2.c | -rw-r--r-- | 731 bytes |
sysctl_net_ipx.c | -rw-r--r-- | 919 bytes |
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